The invention concerns an energy collector for heat pump installations intended for outside placement and comprising a stand and an air-heat exchanger body supported by it, with a heat transfer medium flowing through the body.
Heat pump installations extract thermal energy from the environment and bring it to a higher temperature level suitable for utilization, in particular for heating purposes. Thermal energy may be extracted from the air, the ground, ground water, a flow of waste water or other sources of heat. The process requires heat exchanges which collectively are designated energy collectors.
The present invention relates to an energy collector intended for outdoor placement and primarily serving to extract heat from the air of the environment. Additionally, however, such an energy collector also extracts thermal energy from rain water and solar radiation. The energy collector should therefore provide optimum heat transfer and, in particular, heat transfer without excessive thermal loss. The energy collector should further be of a simple configuration in order to keep manufacturing and maintenance costs low. Since the energy collector is placed in numerous cases in the immediate vicinity of dwellings, it should be aesthetically appealing and small in size, while providing a high heat transfer capacity.
Energy collectors of the afore-mentioned type are known as "energy trees". A stand carries heat exchanger bodies in the form of plates, arranged mostly in a horizontal manner. However, in relation to the external dimensions of the energy collector, the effective surface area that is important with regard to heat transfer efficiency is relatively small. Intensive contact with surrounding area presumes at least a slight horizontal movement of the air. Rain water and solar radiation reach only a very small proportion of the heat exchanger surface and therefore contribute practically nothing to the recovery of heat.
Other energy collectors are known, the heat exchanger whereof consists of bundles of helical tubes through which a heat transport medium is flowing. The tubular coils formed in this manner are located on a cylindrical surface with a vertical axis or on truncated conical surfaces. Rain water flows around this basketlike heat exchanger body which is fully exposed to sun light, but its effective surface is relatively small in relation to its external dimensions. If thin-walled tubes are used, the investment for a support structure is relatively high.
An object of the invention involves providing an energy collector of the afore-mentioned generic type, having a large heat exchange surface around all sides of which the ambient air flows. A further object is that the collector be fully exposed to solar radiation and be characterized by low construction and maintenance expenditures and small dimensions. Another object is that the collector have an appealing appearance, making possible its placement in the immediate vicinity of dwellings.